Method of coloring rubber articles



7 7 Sept. 2, 1930. P. W lT T EN 7 METHOD OF COLORING RUBBER ARTICLES 7 Filed May 19, 1950 Wi en Patented Sept. 2, 1930 UNITED STATES PATENT OFFICE ARTHUR P. 'WITTEN, OF AKRON, OHIO, ASSIGNOR OF ONE-HALF TO GEORGE E- HALL, OF AKRON, OHIO METHOD OF COLORING RUBBER ARTICLES Application filed May 19, 1930. Serial No. 453,625.

This invention relates to coating processes, and it has for its object to provide a dipping method and a novel type of bath whereby marbling or variegated striped color effects may be obtained upon the surface of a rubber article such as a toy balloon.

While the marbling of book edges, Easter eggs, vases, and other articles by dipping them in a bath having a patterned top layer of coloring solution has long been known, this principle has never been successfully applied with rubber solution to the decoration of toy balloons, or similar articles, so far as I am aware. It has been proposed to form a dipped article, such as a balloon, in a bath of rubber solution and to mottle the surface of the article by removing it during this process through a colored, patterned, rubber solution on the upper surface of the bath, said colored solution containing a solvent of lower specific gravity than that used for the main bath. However, in such a method the colored layer difi'uses too rapidly through the bath of rubber solution, and it is in fact wholly impracticable to properly apply the patterned coating in the course of removing the covered form from the bath.

My present invention contemplates forming the rubber article to the desired thickness by the usual successive dippings in rubber solution, and then applying the colored patterned coating and sealing the colors in a single dip, with the use of a suitable bath and superposed layers of material in the manner hereinafter pointed out. The invention further includes an improved mode of obtaining desired patterns on the bath.

Of the accompanying drawings, Fig. 1 is a perspective view, partly broken away and in section, illustrating a dipping form, together with a portion of a dipping tank containing a bath and coating materials thereon arranged for the practice of my invention.

Fig. 2 is a side elevation showing a toy balloon decorated in accordance with my inven-' tion.

Referring to the drawings, 10 is a dipping tank having near one end a transverse partition 11 dividing its interior into a main or dipping compartment and a narrower compartment 12 for the reception of color drippings before, and skimmings after the performance of the coating steps. In the main compartment is placed a bath 13 of a suitable liquid, preferably a volatile hydrocarbon liquid such as carbon tetrachloride or benzol, of which the former is preferred on account of its higher specific gravity, for supporting the upper layers or films of coating materials. Generally speaking, I find that liquids which are solvents of rubber or which have a physical affinity for rubber so as to be capable of spreading over or wetting the surface of a rubber solution rather than congregating in drops thereon, and which at the same time are heavier than the solution and substantially free from any content of rubber, are to be preferred as the material for the bath 13. I do not wholly restrict myself to the use of a single liquid but may employ a mixture.

Upon the surface of the bath 13 is poured a thin layer or film 14 of transparent or puregum rubber solution, indicated in Fig. 1 by stippling. This acts as a sealing layer on the outside of the striped or colored coating to preserve the brilliancy of the colors. 7

Over th layer 14 of pure-gum solution is laid a decorating or pattern layer of pigmented rubber solution or solutions in one or more colors, such as red and green, preferably alternating with each other in the form of spaced narrow stripes. This color layer or collection of narrow films may be applied in parallel lines or stripes 15 by means of a hand tank, extending across the dipping tank 10 and consisting of a row of compartments having individual spouts and containing the alternating colored solutions, said hand tank being, for example, started over the waste compartment 12 in the hands of two operators and then moved over the surface of the layer 14 to deposit the colored stripes thereon. The stripe. layer is shown partly broken away at the left in Fig. 1. The stripes may be relatively slight.- ly wider than indicated in Fig. 1, but are spaced apart from each other in their original arrangement. I' prefer solutions of rubber in petroleum naptha or gasolene for both the pure-gum layer 14 and the colored of one into the other (Infill? e stripes 15. There is practically no dilfusion the short time which elapses between the positing of the to layers and the di ping of the articles.

Vhen the plain anti colored-stripe layers ,14, 15 have been laid, the stripes are preferably rearranged in some fanciful manner to produce a new pattern. I prefer to change the vrelative spacing and direction of the stripes in different parts of the patterned layer by creating a series of curves and nodes therein so that the patterns on a number of a'rt-iclesdipped at the same time in the same tank ma all be different. In the illustration given, tli operators immersing the ends of wires or slmilar small rods in the bath to a point be low the upper layers and drawing said wires across the tank, transversely of the stripes 15, along rather widely spaced parallel lines, giving substantially the effect indicated in ig. 1. The described patterning step or stepsmay, however, be more or less modified. Any air bubbles are pricked out either before or after the arrangement of the stripes.

A number of dipping forms such as 16 will have been covered in the usual manner by successive dippings in rubber solution preferably containing a light pigment such as white or yellow for the ground color, to deposit a seamless hollow film 17 of rubber on the form, and a number of these forms as-' sembled on a dipping tray and the films allowed to dry, for making toy balloons or the like.

The forms 16 bearing the thin rubber articles 17 are then immersed once in the bath 13, and in passing downwardly through the upper layers of rubber solution, the color stripes 15 adhere to the article 17 in a fanciful pattern which differs for each of the several articles. At the same. time the layer 14 of transparent rubber solution becomes deposited upon the article over the colored stripes during the downward dip for sealing the colors and retaining a high gloss after the article has been vulcanized. The remnants of colored solution do not adhere to the sealing layer of clear solution on the article as the latter rises out of the bath.

After draining a short time over the tank, the articles are allowed to dry and are then vulcanized in the usual manner, as by an acid dip, followed by warm-air heating and stripping from the forms.

An example of the decorative effect on the finished article is shown in Fig. 2, in which 17 indicates a toy balloon, and 15 the colored stripes thereon as produced by the above process. The stripes at the base are somewhat widened, apparently by hydrostatic pressure and using upof the color as the immersion proceeds, and may more or less overlap in that region, but they largely retain sharply-defined edges,-and of course the is has been accomplished by the several tail.

The result is a novel and pleasing style of ornamentation never before attained in this art, to my knowledge.

After performing the coating process, the remains of the top solution layers may be skimmed olf into the waste compartment 12, and fresh layers floated on the lower bath 13 of clear solvent for a repetition of the process. After several repetitions, said lower bath 13 will become somewhat darkened with color and may then be distilled to recover said clear solvent.

The foregoing steps and materials may be varied within the scope of my invention as depatterns are infinitely varied in de fined in the claims.

I claim:

1. The method of colorin rubber articles which comprises floating .yers of transparent rubber solution and of colored rubber solution on a bath, immirsing a rubber article in the bath through the level of said layers, causing the color layer to adhere to the article, and the transparent layer to coat the article over said color layer during the downward dip, and removing and vulcanizing the article.

2. Steps in the method of decorating rubber toy balloonswhich comprise floating lay ers of transparent rubber solution and of striped rubber solutions on a bath of clear rubber solvent, immersing the preformed article in the bath through the level of said layers, and causing said striped solutions and said transparent solution to adhere to the article respectively in a partial inner coating and a complete outer coating during the downward dip.

3. The method of coloring a succession of rubber articles which comprises floating layers of transparent rubber solution and of patterned, colored rubber solution on a bath of rubber solvent, dipping an article therein to coat it with the patterned layer, encased by the transparent layer, removing the article, skimming the residue of solution from the bath, and repeating the process with the same bath for a subsequent article.

4. The method of decorating rubber articles which comprises spreading stripes of colored rubber coating on the lower portion of the article by hydrostatic pressure during Y ber solution on a bath of heavier liquid, and

drawing a patterning instrument in the bath across said stripes to rearrange the latter, nodal, curves.

6. A composite dipping bath for rubber articles comprising a lower bath of clear liquid, a layer of transparent rubber solution carried thereon, and a patterned layer of colored rubber solution carried on said transparent solution.

7 A composite dipping bath for rubber articles comprising a ower bath of substantially clear rubber solvent, and a layer of rubber solution floated thereon.

8. A composite bath for rubber articles comprising a lower bath of substantially clear 10 carbon tetrachloride, and a superimposed layer of rubber dissolved in a distillate of petroleum.

In witness whereof Ihave hereunto set my hand this 17th day of. May, 1930. ARTHUR P. WITTEN. 

